Stars and Black Holes Essay -- essays research papers

Below you will read research on stars and black holes. Black holes are stars whose core has been crushed by gravity. In the text to follow you will see how a star forms, read about its life and how it becomes a black hole. Stars are composed of hydrogen gas and dust. Stars owe their existence to the force of gravity. Stars are created from the thinly spread atoms of dust and gas that swirl throughout space. The atoms clump together into dense clouds that eventually collapse under their own gravity. Other forces counteract the gravity. The dust and cloud grows steadily hotter until a nuclear furnace ignites creating a bright shining star. (Couper H. & Henbest N., 1996). Stars are born when particles of hydrogen, helium and dust combine and collapse, shrinking and falling into itself making the cloud hotter. Tiny protons bump into each other and bounce away at high speeds stick together when it is hot enough. Four protons form a particle of helium gas. Two protons fuse together becoming neutrons. Matter that is released from this fusion turns into energy streaming outward from the core creating nuclear fusion. Once the inward and outward forces are equal it reaches its final size and shines, becoming a star. The length of the hydrogen burning stage depends on the stars weight. A star with 15 times the weight of the sun uses up all its hydrogen in less than 10 million years. (Darling D., 1985) The farthest star in the most distant galaxy is more than ten billion light years away. The kind of star a star becomes depends on how much gas and dust the protostar manages to pack into itself as it forms. The more mass a star collects the hotter and brighter it becomes. (Gallant R ., 2000). Three major star types are red dwarfs, yellow dwarfs and blue giants. Red dwarfs are the dimmest and have the longest life span that is about a trillion years. Red dwarfs become black dwarfs when they exhaust their hydrogen and fuel. Yellow dwarf stars have shorter life spans because they burn their hydrogen fuel faster. As fuel runs low they swell up into a red giant, then release planetary nebula, then shrink into white dwarfs and finally cool as black dwarfs. The massive blue giants have the shortest life span as they’ll swell up into supergiants, explode as a supernova and end up as either a neutron star or black hole. (Gallant R ., 2000). A norm... ...un is a ball of gas. It is 8 and one third light years away and 93 million miles away. The suns diameter is 865,000 miles. The sun is about 5 billion years old. (Darling D., 1985). The sun appears as a large disk. At the top of the sun you can see two huge gas eruptions called prominences. These prominences leap out hundreds of thousands of miles. They have hair like spikes that are surges of hot gas called spicules. The mottled effect is caused by cells of hot gases welling up from beneath the surface, cooling and appearing darker than the surrounding gases. (Gallant R ., 2000). Therefore, the sun, stars and black holes coexist with one another in the solar system along with other matter in the galaxy. The sun is a star. Black holes are collapsed stars. Each does not exist without the other. References Couper H. & Henbest N. (1996). Black Holes. New York, NY: DK Publishing Inc. Darling D. (1985). The Stars from birth to black hole. Minneapolis, Minnesota: Dillon Press Inc. Gallant R . (2000). The life stories of Stars. Tarrytown, New York: Benchmark Books Sipiera P. (1997). Black Holes. Canada: Children’s Press, Grolier Publishing Co. Inc